This document summarizes a study on the design and development of an ergonomic motorcycle seat. The researchers aimed to improve rider comfort by considering anthropometric data and analyzing vibration and discomfort. They designed a new seat with a backrest and extended cushion. Discomfort was assessed using RAMSIS software, showing reductions in various body parts from the original to modified seat. Whole-body vibrations transmitted through the seat affect health, so the researchers addressed factors like ergonomic design and damping to reduce vibration exposure.

1. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 12, December (2014), pp. 09-15 © IAEME
9
DESIGN AND DEVELOPMENT OF MOTORCYCLE SEAT
FROM ERGONOMICS POINT OF VIEW WITH
VIBRATION AND DISCOMFORT ANALYSIS
Dr. M. M. Patil1
, Dr. Lokesh Bajpai2
, Dr. P. L. Verma3
1
Department of Mechanical Engineering, J.T.M.C.O.E. Faizpur, Maharashtra, India
2, 3
Department of Mechanical Engineering, SATI Vidisha, Madhya Pradesh, India
ABSTRACT
Today, a rebellious race is taking place among the automobile industry so as to produce
highly developed models and the automobile industry has seen a market shift towards sport-utility
vehicles. In order to maintain the level of comfort that customers expect from vehicles and still
maintain the high safety standards of automobiles, attempts are made to develop an ideal vehicle
(motorcycle) which is aesthetically pleasing, ergonomically running and most important is safety.
This work solves the problems of human discomfort procured from riding the motorcycle. Also
comprises the task of ergonomic considerations in motorcycle seat design using anthropometric data
of riders.
Keywords: Ergonomics, Motorcycle, Seat, Vibration Analysis.
1. INTRODUCTION
Implementations of new technology to the work always give best results when it is coupled
with human resource function. In present scenario there is cut-throat competitions in the corporate
world, due to which customer demands have increased drastically. The human–machine approach
enables key areas to be identified irrespective of a particular system so that ergonomics can be
applied consistently in different system. The common concept of machine is virtually any type of
object, device, equipment, facility that people use in carrying out some activity that is directed
towards achieving some desired purpose or performing some function. Ergonomics is a systematic
use of the knowledge concern to relevant human characteristics in order to achieve compatibility in
the design of interactive systems of people, machines, environments, and devices of all kinds to
ensure specific goals. Such goals include improved system effectiveness, productivity, safety, ease of
performance and the quality of life. Aesthetics takes care of customer attraction and ergonomics is
INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING AND
TECHNOLOGY (IJMET)
ISSN 0976 – 6340 (Print)
ISSN 0976 – 6359 (Online)
Volume 5, Issue 12, December (2014), pp. 09-15
© IAEME: www.iaeme.com/IJMET.asp
Journal Impact Factor (2014): 7.5377 (Calculated by GISI)
www.jifactor.com
IJMET
© I A E M E

2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 12, December (2014), pp. 09-15 © IAEME
10
responsible for customer’s safety and human comfort by reducing stress during working or driving
an automobile. Rider posture is an important factor which is to be considered in the ergonomic
design process of motorcycle. Most decisions during motorcycle design and manufacture are
informed by studying the intricate biomechanical components of human musculoskeletal systems to
insure maximum comfort, safety and well-being during riding the motorcycle. The effectiveness of
virtual riding instruction can be increased when techniques automatically distinguishing between
violations and errors are available.
1.1 Problem Definition
After considering facts the author felt that a greater need to enhance comfort characteristics
during vehicle design process has recently forced the auto-manufacturers to develop new model
preparation approaches. So, in this paper a new model preparation approach from ergonomics point
of view of a motorcycle seat is proposed to predict the ride comfort. A new model is created for
calculating ride comfort effectively. The responses of seat surface have observed at various
excitation frequencies. To find the optimum values of each parameter, an optimization process was
executed properly and added in the model. Using this model, the best possible ride comfort values
are computed without the need of physical prototypes. The developed algorithm can be very helpful
as an assistant tool for engineers during vehicle design and manufacturing process.
Vehicle ride comfort is one of the most prominent factors affecting purchase decision and
customer satisfaction. Meeting the customer comfort requirements, which is a popular issue, plays an
important role in terms of vehicle marketing. Therefore in recent years, the number of studies on
developing the techniques to optimize the vehicle ride comfort characteristics is gradually increasing
to meet the customer requirements. Although various numerical and experimental studies were
employed, studies related to the solution of this problem are not at a desired level yet. Generally, it is
studied with the models which have uncertainties because of the complexity of models and boundary
conditions. Therefore for ergonomics consideration new approaches are required to evaluate the ride
comfort characteristics for vehicle dynamics and comfort studies. The main contribution of this work
is to remove or reduce the uncertainties existing in the current studies on the subject of vehicle
development process.
Normally rider feels different vibrations from seat surface, feet region and handle bar during
driving process and due to such type of vibration driver feel discomfort. So, in this paper a special
care has been taken by the author to sort out such type of problems, which will be more suitable as
per ergonomics point of view. To design any engineering component, it is necessary for the designer
to take care of the end users, in most of the cases human beings are involved. So to design a
motorcycle seat from ergonomics point of view, it is important for the designer to consider the
anthropometric data of human being. Accordingly the necessary modifications will be possible to
sort out such type of problems.
1.2. Seating Comfort
The motorcycle seat is characterized by having multiple shape that provide a balance
between the static seating comfort and the comfort required for the various riding positions of the
motorcycle model concept. In conventional seat development, design parameter for example
hardness, shape and materials have been directly manipulated based on subjective filling evaluations.
However, this made it difficult to predict the effect of changing design parameters. Body pressure
distribution is influenced by personal attribute of the test subject, like seating area caused by, for
example, differences in postural side and bone structure. Seats are generally design to fit at least 90
percentile of the population [5] from small to large body sizes. Static and dynamic geometry of the
human body are used in seat design. Static geometry is obtained from anthropometric studies of the
population. Dynamic geometry is obtained with a mechanical model of the human body. Mass-links

3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 12, December (2014), pp. 09-15 © IAEME
11
are positioned to represent seated posture. The human body is evolved in such a way that, when the
body is seated, the primary weight of the body can best be supported by the ischial tuberosities some
time called the sitting bone of buttocks. The primary weight should be supported by these bones. The
seat design should be such that it should provide for a distribution of the weight over the entire
buttocks, with the pressure decreasing from these bones to the periphery of the buttocks. A major
portion of the vibration experienced by the rider and pillion of a motorcycle enters the body through
the seat. Whole body vibrations (WBV) are vertical vibration, tends to affect the human body
mostly. These vibrations are transmitted to buttock and back of rider and pillion along the vertebral
axis via the base of seat. An ergonomic design approach plays a crucial role for improving the riding
comfort.
2. MOTORCYCLE SEAT WITH BACKREST DESIGN FROM ERGONOMICS POINT OF
VIEW
To avoid the problem related to backache and testicle pain which is observed during survey
of motorcycle riders, the seat design needs to be improved from the ergonomics point of view from
the average of all seasons namely summer, rainy, and winter. Testicle pain and toe/ankle pain is
having sufficient percentage pain which can be considered while designing the seat of motorcycle.
Generally the motorcycle seat is designed with aesthetic point of view which gives good look to
overall motorcycle model. In new generation the trend is to select the motorcycle according to power
and its aesthetics look. But the seats are not designed according to ergonomics which plays a vital
role in human comforts. Considering the severity of pain factor the seat of motorcycle is redesigned
according to anthropometry of riding populations, rider’s problems and their opinions about comfort.
While riding the motorcycle, there is continuous change in body position due to acceleration and
braking of motorcycle. This results pain in testicles of riders but this factor is not considered while
designing the seat of the motorcycle. In new design cushion is extended on the fuel tank upto 100
mm. so that movement of the body will not cause problem to the testicle.
For 90th
percentile the buttock knee distance, knee height (sitting) and thigh clearance height
(sitting), 61, 57, 60 respectively are three lengths of a triangle. As a result, the angle between the
thigh and the lower leg is 63 degree; however the range for a comfortable angle is 80 to 85 degree. If
we were to try and find a person who will be able to sit himself comfortably on the front seat, it
would mean that the design is not suitable for normal person, which may be suitable for a person
with buttock knee distance of 250 mm. and knee height 600 mm. which is not found for any person.
To provide more comfort while riding the motorcycle, the seat with backrest is designed which is as
shown in Figure 1. The backrest attached to the seat is having height of 100 mm. above seat surface
which will give comfortable riding posture of the rider and the rider will not face any problem during
long distance traveling in motorcycle.
Fig. 1: Soft Model of Motorcycle Seat using Pro-E

4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
ISSN 0976 – 6359(Online), Volume 5, Issue 1
Fig. 2: Fabrication Process for Modified Seat
Similarly backseat to back footrest distance must be considered from anthropometric data.
Due to improper design the pillion on motorcycle exerts a force on rider due to slipping when brakes
are applied. It will develop backache within a very
3. DISCOMFORT ASSESSMENT BY RAMSIS BODY BUILDER VERSION
To conduct human discomfort assessment of the motorcycle in this work, the original model
and modified model in IGS format was supplied to EDS technologies Pvt. Ltd Bangalore, for
software (RAMSIS Body Builder version 1.4
during the study. Figure 3 shows the discomfort assessment for original motorcycle seat model and
modified motorcycle seat model with reference to the eight steps scale from RAMSIS.
Fig. 3: Discomfort Assessment for Modified Motorcycle
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
6359(Online), Volume 5, Issue 12, December (2014), pp. 09-15 © IAEME
12
Fabrication Process for Modified Seat of Motorcycle
Similarly backseat to back footrest distance must be considered from anthropometric data.
Due to improper design the pillion on motorcycle exerts a force on rider due to slipping when brakes
are applied. It will develop backache within a very short time.
3. DISCOMFORT ASSESSMENT BY RAMSIS BODY BUILDER VERSION
To conduct human discomfort assessment of the motorcycle in this work, the original model
and modified model in IGS format was supplied to EDS technologies Pvt. Ltd Bangalore, for
software (RAMSIS Body Builder version 1.4-3.8.30) analysis the anthropometri
during the study. Figure 3 shows the discomfort assessment for original motorcycle seat model and
modified motorcycle seat model with reference to the eight steps scale from RAMSIS.
Discomfort Assessment for Modified Motorcycle Seat (RAMSIS)
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
© IAEME
of Motorcycle
Similarly backseat to back footrest distance must be considered from anthropometric data.
Due to improper design the pillion on motorcycle exerts a force on rider due to slipping when brakes
3. DISCOMFORT ASSESSMENT BY RAMSIS BODY BUILDER VERSION
To conduct human discomfort assessment of the motorcycle in this work, the original model
and modified model in IGS format was supplied to EDS technologies Pvt. Ltd Bangalore, for
3.8.30) analysis the anthropometric data collected
during the study. Figure 3 shows the discomfort assessment for original motorcycle seat model and
modified motorcycle seat model with reference to the eight steps scale from RAMSIS.
Seat (RAMSIS)

5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
ISSN 0976 – 6359(Online), Volume 5, Issue 1
Table-1: Percentage Reduction in Discomfort (RAMSIS)
Sr.
No
Parameters
/Body Parts
1 Fatigue
2 Discomfort
Feeling
3 Neck
4 Shoulders
5 Back
6 Buttocks
7 Left Leg
8 Right Leg
9 Left Arm
10 Right Arm
11 Spinal Column
4. VIBRATION AND ITS EFFECT ON HEALTH OF RIDER
The factors such as ergonomic design, damping and attenuation, resonance and many more
have a great influence on the exposure characteristics and intensity levels of vibration exposure
experienced by machine operators. The human body can tolerate certain l
but starts to deteriorate and cause long term damage and disruption of the natural processes of the
body. The drivers of automobiles are subjected to different magnitude of the vibrations while
driving/riding. The magnitude of t
body weight, age of automobile, type of seating, type of suspension and road surface factors. These
vibrations are transmitted to the buttocks and back along the vertical axis via the base a
of the seat. On the other hand, the
feet and hands of rider. During motorcycle riding, due to its unbalancing nature, it creates enormous
vibration and affects the bioelectric p
Fig. 4: Detailed
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976
6359(Online), Volume 5, Issue 12, December (2014), pp. 09-15 © IAEME
13
Percentage Reduction in Discomfort (RAMSIS)
Original
Motorcycle Value
Modified Motorcycle
Value
3.6 2.9
4.6 3.8
3.5 2.6
3.5 2.5
2.1 2.1
1.9 1.6
3.5 1.6
3.2 2.1
2.1 2.8
2.4 2.4
4.2 4.2
4. VIBRATION AND ITS EFFECT ON HEALTH OF RIDER
The factors such as ergonomic design, damping and attenuation, resonance and many more
have a great influence on the exposure characteristics and intensity levels of vibration exposure
experienced by machine operators. The human body can tolerate certain levels of vibrational energy
but starts to deteriorate and cause long term damage and disruption of the natural processes of the
body. The drivers of automobiles are subjected to different magnitude of the vibrations while
driving/riding. The magnitude of the vibration also depends on the type of automobile, engine size,
body weight, age of automobile, type of seating, type of suspension and road surface factors. These
vibrations are transmitted to the buttocks and back along the vertical axis via the base a
of the seat. On the other hand, the footrests and steering handle transmit additional vibration to the
feet and hands of rider. During motorcycle riding, due to its unbalancing nature, it creates enormous
vibration and affects the bioelectric phenomenon.
Detailed Drawing for attachment of Spring to the FRP Plate
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
© IAEME
Percentage Reduction in Discomfort (RAMSIS)
% value of
Discomfort
19.44
17.39
25.71
28.57
---
15.79
54.29
34.38
---
---
---
The factors such as ergonomic design, damping and attenuation, resonance and many more
have a great influence on the exposure characteristics and intensity levels of vibration exposure
evels of vibrational energy
but starts to deteriorate and cause long term damage and disruption of the natural processes of the
body. The drivers of automobiles are subjected to different magnitude of the vibrations while
he vibration also depends on the type of automobile, engine size,
body weight, age of automobile, type of seating, type of suspension and road surface factors. These
vibrations are transmitted to the buttocks and back along the vertical axis via the base and the back
and steering handle transmit additional vibration to the
feet and hands of rider. During motorcycle riding, due to its unbalancing nature, it creates enormous
Drawing for attachment of Spring to the FRP Plate

6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 12, December (2014), pp. 09-15 © IAEME
14
Physical factors that influence the effects of vibration on rider during riding are acceleration
and frequency, duration of exposure, automobile maintenance and protective practices. Biodynamic
factors like grip force, position of the hand/arm relative to body, texture and type of material of the
handle causes the effect. Individual factors like operator’s control, automobile speed and skill of
driving and individual susceptibility to vibration also leads to the effect.
Table 2: Frequency of Excitation and Amplitude of Main System
(Motorcycle) Seat (current 1.2 amp)
Excitation
Frequency
Amplitude of Vibration (mm) % Reduction in
Amplitude of Vibration
Original Seat Modified Seat
50 2.3 1.2 47.83
67.17 3.9 3.4 12.82
75.00 1.1 0.60 45.46
100. 0.90 0.30 66.67
125.62 0.60 0.21 65.00
127.00 0.35 0.15 57.14
130.01 0.10 2.20 ---
150.00 0.75 0.40 46.67
175.00 3.1 0.35 88.71
200.000 1.9 0.30 84.21
225.00 0.70 0.22 68.57
290.00 0.55 0.20 63.64
300.00 0.97 0.90 7.22
320.21 1.0 1.75 ---
329.67 2.15 0.70 67.44
500.00 1.12 0.12 89.29
Fig. 5: Excitation Frequency v/s Amplitude of Vibration
A Fiber-Reinforced Polymer sheet is used to attach the helical compression spring designed
to quench the vibrations. There are two basic equations for the design of the helical springs which
are, the load-stress and the load-deflection. A helical spring has round wire of diameter 1.5 mm, are
attached to the FRP sheet of 3 mm thickness as in Figure 4. Such 20 springs are attached to the same
sheet. Table 2 gives the percentage reduction in amplitude of vibration. Figure 5 shows the graphical
presentation of amplitude of vibration of the original and modified motorcycle seat.
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0 100 200 300 400 500 600
Amplitude
Excitation Frequency
Original Seat
Modified Seat

7. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 – 6340(Print),
ISSN 0976 – 6359(Online), Volume 5, Issue 12, December (2014), pp. 09-15 © IAEME
15
5. CONCLUSION
Various engineering data have been overcome during this work. There are many factors
which disturb human comfort while one uses the motorcycle. While analyzing the observed pains
like back pain, hip bone pain, testicles pain, toe / ankle pain, lumber spin pain, body position,
environmental condition and mental or work load. As per ergonomic consideration seat with back
rest is prepared by using Pro-E software which may give positive results and provide good riding
comfort to the operator of the motorcycle. It is always advisory to incline our body 0-5 degrees to the
front position at straight vertical position while riding the motorcycle. The new modified seat
fabricated, reduces the driving discomfort during prolonged usage of motorcycle. The discomfort
analysis conducted with RAMSIS software for validation purpose, on original motorcycle model and
modified motorcycle seat (Table 1) which shows that, percentage reduced in discomfort is in the
range of 15 percent to 54.29 percent.
To check the amplitude of vibration at different frequency of excitation first off all, original
seat of the motorcycle excited from 50Hz. To 500Hz and the amplitude of vibration for the same are
tabulated in the Table 2. The same procedure has been repeated for the modified seat. It is greatly
interesting to know the results, that the percentage change in the amplitude of vibration changes from
7.22 percent to 89.29 percent. To validate this result from the standard result prescribed by ISO
2631-1, 1997, the first mode of natural frequency, 50 Hz. compared with the standard table. It is
clearly mentioned in the table that if vehicle vibrates with 10 Hz to 90 Hz. frequency, it effects on
the human body to degrade the visual action and finally on driving performance. Though from the
Table 2, it is clear that at 50 Hz. frequency of excitation, the amplitude of vibration of modified seat
reduced by 47.83 percent which enhance the visual action of the driver to a great extend and driver
will feel discomfort during prolonged use of motorcycle. So, the results obtained experimentally are
close agreement with the result prescribed by ISO 2631-1, 1997.
REFERENCES
[1] Shamasundara B.V. and Ogale M.S., (1999), “Ergonomic Study on Indian Driving
Population”, Symposium on International Automotive Technology, ARAI, Pune, SAE No.
990021, pp. 255-267.
[2] Bridger R.S., “Introduction to Ergonomics,” Taylor & Fancies Inc. Group London & New
York, PP. 33-57 and 436-476, 2nd
edition 2003.
[3] Eric Little, Patrick Handrickx, Phil Grote, Maurice Mergay and Jim Deel, (1999), “Ride
Comfort Analysis: Practice and Procedures”, Symposium on Indian Automotive Technology
at ARAI, Pune (SIAT), No.- 990053, pp. 503-508.
[4] Karen I., Kaya N., ozturk F., Korkmaz I., Yildizhan M.and Yurttas A., (2012), “ A Design
Tool to Evaluate the Vehicle Ride Comfort Characteristics: Modelling, Physical Testing, and
Analysis”, International Journal of Advanced manufacturing Technolgy Vol. 60, pp. 755-763.
[5] Adams Michael A. and Patricia Dolan, 2005, “Perspective Spine Biomechanics”, Journal of
Biomechanics, Vol.-38, pp. 1972-1983.
[6] Shivakumar B.S. and Sridhar V., (2010), “Study of Vibration and its effects on Health of the
motorcycle rider,” online Journal of Health and allied Sciences, Manglore, South India: ISSN
0972-5997, Vol. 9, Issue 2, pp.1-4.
[7] “Terms and Definitions of Dimensions of Motorcycles,” Indian Standards Institution, New
Delhi, IS: 11432-1985, pp, 1-7, (Adopted Sept 27th
, 1985).
[8] R S Rajpurohit and R S Prasad, “Analysis of Mechanical Structure Under Vibration using
Vibration Measuring System”, International Journal of Mechanical Engineering &
Technology (IJMET), Volume 4, Issue 1, 2013, pp. 134 - 141, ISSN Print: 0976 – 6340,
ISSN Online: 0976 – 6359.